<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	</body>
	<script type="text/javascript">
		var users = [
{name: "张含韵", "email": "zhang@email.com"},
{name: "江一燕",   "email": "jiang@email.com"},
{name: "李小璐",  "email": "li@email.com"}  
];

var emails = users.map(function (user) { return user.email; });
//获取所有的关于数组里面的每一项，返回一个新的数组
//console.log(emails.join(", "));  

var numA = 1;
var numB = 5.22; 
console.log(numA + numB)
Math.formatFloat = function(f, digit) {
    var m = Math.pow(10, digit);
    return parseInt(f * m, 10) / m;
}
console.log(Math.formatFloat(numA + numB, 2))



	</script>  
</html>
